Health literacy is defined as a combination of attributes that can explain and predict one's ability to access, understand, and apply health information. Approximately 90 million American adults lack these necessary skills. To date, studies of health literacy have used tests of reading recognition or tests of reading comprehension and numeracy to categorize health literacy status. No studies have included writing, speaking, or listening skills, and none have included cultural factors or basic conceptual knowledge - all thought to contribute to health literacy. The lack of basic conceptual knowledge data is particularly important because knowing how to prevent and manage disease depends not only on one's reading comprehension and numeracy skills, but also on one's ability to place that information in a meaningful context. Researchers hypothesize that oral health disparities are influenced by health literacy, although little research has been done to support that position. The overall goal of the proposed research project is to study health literacy in an oral health context while including a measure of basic conceptual knowledge in the analysis. The specific aims of the proposed research project are to: 1) develop a valid instrument to assess basic conceptual knowledge of oral health and illness; 2) develop a valid instrument to assess knowledge of oral disease prevention and management; and 3) determine to what extent basic conceptual knowledge exists as an effect modifier of the association between reading comprehension and numeracy and knowledge of oral disease prevention and management. The two knowledge instruments will be developed with the guidance of an expert panel and tested for reliability and validity during pilot testing. Associations between reading comprehension/numeracy and knowledge of oral disease prevention and management will be tested among a probability sample of adults from the Baltimore metropolitan area. Public health relevance: Successful completion will show how basic conceptual knowledge interacts with reading comprehension/numeracy, and how it is associated with knowledge of oral disease prevention and management information. Deterrmining this association will advance understanding of health literacy in oral health research and will guide the development of appropriate health information for persons with all levels of health literacy. It is anticipated that these results will ultimately improve oral health and eliminate disparities in the United States. [unreadable] [unreadable] [unreadable]